The New York Post’s “scoop” on Dominique Strauss Kahn’s accuser is getting fishier, to the extent that’s possible. The paper appears to have had documentation challenging the reliability of its only source in a story alleging that the accuser had worked as a prostitute.

To reprise the tabloid’s story: The New York Post reported on July 2 that DSK’s accuser had worked as a prostitute — a piece that triggered an immediate libel suit from the woman. For its salacious bit of reportage, the newspaper relied on a single, anonymous person, identified as “a source close to the defense investigation.”

The source coughed up two key details:

1) That the accuser did special favors for male guests at the Sofitel Hotel and received compensation in return;

2) That her union had placed her there because it knew she would “bring in big bucks.”

After floating that second allegation, the New York Post wrote nearly 30 paragraphs of copy blasting the accuser from various angles. Then it dropped in a denial of the union claim. “These allegations are absurd,” the paper quoted union spokesman Josh Gold as saying. “She never registered at our hiring hall. We never sent her for a single interview. We absolutely did not place her at the hotel and we do not track tips.”

And that’s pretty much the way it was left: The New York Post’s anonymous source versus a named union spokesperson.

What was left unsaid was that the union had sent documents — an employment packet, basically — to the New York Post supporting its contentions about the accuser, according to Gold. The file included the accuser’s application for work at the Sofitel, plus a cursory evaluation by management.

Clues as to how the woman may have ended up looking for work at the Sofitel are in the papers. The application asks how the applicant had learned of the hotel; the woman checked a box for “Agency.” In the “references” portion of the application, the woman put down a worker with the International Rescue Committee (IRC), an agency that assists refugees with employment, among other things. When contacted about the accuser, IRC declined comment, citing policy not to talk about individual cases.

Nowhere on the form did the applicant mention a union.

So did the New York Post review the documents that the union claims to have passed along? That’s hard to say. Several of my inquiries to the paper have ended in frustration — most commonly with a reference to the paper’s PR shop. An e-mail to New York Post spokesperson Suzanne Halpin hasn’t yet fetched a response.

The back-and-forth between the union and the New York Post may explain something about the accuser’s libel suit. Lawyers for the accuser allege that “Defendant New York Post knew, or should have known” that statements in the story were “false before it was published.”

To use the paper’s own language, this “stunning new info”casts doubts on whether the woman was a “hooker,” “working girl,” not to mention a “scam artist.” The hotel manager who reviewed her, by the way, checked boxes on the evaluation form alongside “Speaks well, expresses ideas adequately”; “Sincere desire to work”; and “Likeable.” On the “overall impression,” the woman scored a “very good.”